There are a variety of infectious human diseases, such as human respiratory tract infections, that are caused by human pathogens such as bacteria, fungi and viruses. For example, viral causes of infectious human diseases (and their associated diseases) include: Influenza A virus (influenza); Influenza B-C virus (coryza; ‘common cold’); Human adenovirus A-C (various respiratory tract infections; pneumonia); Human Para-influenza virus (coryza; ‘common cold;’ croup); Mumps virus (epidemic parotitis); Rubeola virus (measles); Rubella virus (German measles); Human respiratory syncytial virus (RSV) (coryza; ‘common cold’); Human coronavirus (SARS virus) (SARS); Human rhinovirus A-B (coryza; ‘common cold’); parvovirus B19 (fifth disease); variola virus (smallpox); varicella-zoster virus (herpes virus) (chickenpox); Human enterovirus (coryza; ‘common cold’); Bordetella pertussis (whooping cough); Neisseria meningitidis (meningitis); Corynebacterium diphtheriae (diphtheria); Mycoplasma pneumoniae (pneumonia); Mycobacterium tuberculosis (tuberculosis); Streptococcus pyogenes/pneumoniae (strep throat, meningitis, pneumonia); and Haemophilus influenzae Type B (epiglottis, meningitis, pneumonia).
Many of the human viral respiratory tract infections result in significant morbidity and mortality. For example, seasonal epidemics of influenza viruses worldwide infect an estimated 3 million to 5 million people, and kill between 250,000 to 500,000 people each year. In addition, cyclical influenza virus pandemics occur, such as the influenza outbreak in 1918 which killed approximately 20 million people worldwide.
The mode of transmission of one or more than one human pathogen that causes human respiratory tract infections was believed to be primarily by direct skin to skin contact; however, it has been shown that many human pathogens are also spread by airborne transmission of pathogen-laden droplets expelled from the respiratory tract of infected individuals by coughing or sneezing, or by simple exhalation.
Vaccines are available against some human pathogens that cause human respiratory tract infections, and medications have been developed that are effective against some of the human pathogens. Vaccines, however, do not provide immediate protection but require time sufficient for development of an antibody response before they can reduce the transmission of the human pathogen. Additionally, effective medications that can reduce transmission are not available for most of the human viral pathogens and for some of the human non-viral pathogens.
Therefore, there is a need for a new method for preventing airborne transmission of one or more than one human pathogen that causes human respiratory tract infections, among other diseases.